As always there is no absolute answer. As far as I can see in your situation, I'll give you a few options
Don't fight with her. If it's a close friend, ask why she wants to fight and find methods to resolve it if you want to avoid violence. For example, talking in a public area where you're less likely to make a scene. Keep a calm face and at the least, fake pretend that you are holding the reins of the conversation. Can be applied to most situations (because it's vague).
Fight. In this situation anything can go. If you are beaten to a pulp, weigh your chances and if the pros outweigh the cons, go ahead and tell. If it escalates to something more than just fighting, in example attempted murder, TELL, well tell if you value life. If you don't, someone does and look at it this way, if you don't value your life, someone else has a better use for you.
If you end up beating them up... you did good. If they started the fight come in from the point of self defense and testify that she started it. Whether or not you guys may still hold resent towards each other is up to your attitudes, but if you act as the higher man you're bound to get somewhere.
Use extremes. Tell everyone about the fight. This will most likely head in either two ways. One, the preferred, the offender will back off. Or Two, you end up fighting in a public manner, usually with the attacker being cautious of getting in trouble since the fight is publicly known.
If the persons dead out for you, tell a couple close friends or random students, but make sure someone gets word of the situation.
And know the most general answer. Don't tell. If you look hard enough you'll probably find out why you don't want to tell on her. Maybe because you don't really care enough to tell, or you hold residual feelings towards the girl.
That's 'bout it.
Coming from a sadomasochistic failure of a student counselor in highschool who enjoys fighting and sees it as a form of exercise.
Hoped I Helped
If your boyfriend wants to fight someone else he hates, just tell him this tearful phrase:If you fight with someone else will never go out with you ever again and then his life is smooth.
Tell him you are waiting for someone else.
he wants to hang out with you, dont lie to him and tell him. thats the main reason a boy will ask, because he wants to go out with u.
you dont... it just happens.
Just tell them you dont want them and if its someone who you dont like getting emails from, block them.
First I'll fight with him , and then I'll give him a treat for fighting.....! And I'll tell him that he can fight again if he wants .
a tell him what u mean
Fear
tell him that if he really wants you that he should show it or else your going to leave him for someone else
i dont really know i need someone to tell me i dont really know i need someone to tell me
i dont know someone please tell me i dont know someone please tell me
Now in days no one wants to be seen as scary, everybody has some thing to prove to one another. In these cases its best to walk away from a fight in order to live to see another day. If that person wants to fight you tell someone: principal, parent, police, ect. whoever it takes to get that person off your back. Its never worth the risk.